The present invention relates to a device for forming an inserting hole, and more particularly to a device used for forming an inserting hole for an endoscope, a drainage tube and the like. The inserting hole for an endoscope serves to allow insertion of the endoscope into diseased portions of the body in the treatment of cholangia diseases, nephrosis and the like, while the inserting hole for a drainage tube serves to allow insertion of the drainage tube into diseased portions of the body and removal treatment of bile, calculus and the like in the treatment of cholangia diseases, nephrosis and the like. Though the device of the present invention can be used for forming an inserting hole for an endoscope, a drainage tube and the like as stated above, the following explanation is mainly based on a device for forming an inserting hole for an endoscope.
Hitherto, percutaneous treatments using endoscopes have been carried out for various sickness in the bile duct, cholecyst, renal pelvis or ureter. That is, fibrous cells are formed around a tube as a reaction of the organism to foreign material by percutaneously inserting the tube having a diameter of 5 to 6 mm necessary for the insertion of the endoscope into duct organs such as bile duct, cholecyst, renal pelvis and the like. A fistula is thus formed and the endoscope is put in or out through the fistula to carry out the treatment.
In the conventional endoscope treatment, a small diameter tube is gradually exchanged at an interval of few days to one week for such tube as having a larger outer diameter in about an month, thereby forming a large diameter fistula allowing the insertion of endoscopes. Thus, the conventional method has problems that it takes a lot of time to form a fistula and gives a great pain to a patient.
As a method for shortening a period required for the above-mentioned operation or treatment, there is proposed, in Japanese Unexamined Utility Model Publication No. 78938/1987, a set for expanding a fistula for bile drainage comprising a small diameter tube allowing a metallic guide wire to pass through a center thereof, a medium diameter tube covering an outer periphery of the small diameter tube, and a large diameter tube covering the outer periphery of the small diameter tube and having an outer diameter larger than that of the medium diameter tube.
In various treatments using an endoscope such as lithotripsy, polypectomy and the recovery of the removed tissue, however, it is necessary to completely pull out the endoscope many times while holding the tissue or calculus. Therefore a fistula between the chest wall and the surface of the liver or between the retro abdominal wall and kidney is required to adhere securely. A large diameter tube having a diameter of 5 to 6 mm is required to be kept in the fistula for a few weeks to complete the formation of a strong fistula. Such method gives a great pain to a patient.
Further, there is proposed another device in which an endoscope is inserted into a hollow portion of a large diameter tube while leaving the large diameter tube in the body. In such a device, however, a diaphragm positioned on the boundary between lungs and a liver moves up and down each time a patient breathes, and the liver moves up and down with the movement of the diaphragm. As a result, there is caused a problem that the position of the large diameter tube moves. There is also a problem that a part of the large diameter tube positioned on the boundary between a chest wall and a surface of the liver bends each time a patient breathes, and the large diameter tube is broken.
In order to solve the above-mentioned drawbacks, the present inventors have variously investigated and found out that the above-mentioned drawbacks are solved by applying a tube having a longitudinal tearing line described in, for example, Japanese Examined Utility Model Publication No. 10698/1986 to a largest diameter tube, by tearing a part of the tearing line to fold one end of the tube, and by sewing the folded portion of the tube on a skin of the patient to fix the largest diameter tube.
The above tearing lines of tubes are conventionally formed by means of a knife cutter or a heat cutter. In the case of the tearing line formed by means of a heat cutter, however, both edges of a cut portion 14 are bulged due to heat of a heat cutter as shown in FIG. 9 illustrating a section of a thick-walled portion of a tube, so that a surface of the thick-walled portion shrinks and deforms at the bulged portion. Accordingly, a tissue of the body is sometimes injured when the tube is inserted into or pulled out from the body. Further, a tube is not necessarily opened along a tearing line when the end of the tube is outwardly opened with hands. Still further, in the case of a knife cutter, if the knife cutter is not sufficiently sterilized, there is a danger that bacteria adhere to a cut portion when cutting a tube so that subcutaneous tissue or duct organs such as bile duct of a patient are contaminated.
In particular, it is difficult in the case of these cutters to adjust length and width of the cut portion of the tube to desired values, so that tubes having predetermined quality are hard to obtain. Therefore, a tube is pressed by a pressure of subcutaneous tissue so that a tearing line thereof is sometimes broken to damage cell tissue. Moreover, the tearing line of the tube formed by these cutters has a large cutting width. Accordingly, a patient is sometimes infected with bacteria adhered to a cut portion of the tube, and tissue of the body is injured when inserting or pulling out a tube.
It is an object of the present invention to provide a device for forming an inserting hole capable of reducing damage of tissue of the body as much as possible and carrying out operations or treatments using endoscope or drainage tube in a short time.